After the last entry and discovering that the at trick still works, I asked myself this question: do tasks created through Control Panel > Scheduled Tasks need the Task Scheduler service?
Sadly, they do.
However, I don't currently have any scheduled tasks, so I've disabled the service. If you want to do the same, either use the Services MMC snap-in, or you can use sc...
sc config schedule start= disabled
Edit (2004-09-02): OK, I've re-enabled it. A number of readers (I have readers?!?) mentioned that a number of system optimisation features also run using the Schedule service, something I confirmed with Filemon. Obviously the ability to create a job that starts as LocalSystem is a bit disconcerting, but it seems that this can only be done locally by an authenticated administrator. I'd prefer to have a separate optimisation service, but you can't have everything.